Police defended their use of tear gas and water hoses to quell a riot near Washington State University that sent 23 officers and several students to the hospital.

The disturbance started early Sunday when police went to investigate a car accident and were met by many as 200 people outside a party.Members of the mob pelted police with beer cans and rocks during the five-hour melee. Three students were arrested.

"They were completely out of control," Whitman County Sheriff Steve Tomson said. "We're absolutely lucky that nobody got killed up there."

Most of the injured officers were treated for minor cuts and bruises and released, university spokeswoman Barbara Petura said.

Authorities were unsure what prompted the violence, although some students blamed recent crackdowns on alcohol at fraternities and other off-campus housing.